javascript checkbox全选和反选的简单实现

function tempUser(val){    $("input[name='userid']").each(function() {       this.checked = val;    }); } 

<input type='checkbox' onclick="tempUser(this.checked)" /> <input type='checkbox' name="userid" /> <input type='checkbox' name="userid" /> <input type='checkbox' name="userid" /> <input type='checkbox' name="userid" /> <input type='checkbox' name="userid" /> <input type='checkbox' name="userid" /> <input type='checkbox' name="userid" />